The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a high mobility channel after dummy gate removal in a III-V compound semiconductor-containing field-effect transistor (FET).
The term “III-V compound semiconductor” denotes a semiconductor material that includes at least one element from Group III of the Periodic Table of Elements and at least one element from Group V of the Periodic Table of Elements. Typically, each of the III-V compound semiconductor layers is a binary, ternary, or quaternary III-V containing compound. Examples of III-V compound semiconductors that can be used in the present invention include, but are not limited to, alloys of InGaAs, InAlAs, InAlAsSb, InAlAsP, and InGaAsP.
Compound III-V semiconductors may be desirable for use as channel materials for advanced ultra large scale integration (ULSI) digital logic applications due to their high electron hole mobility as compared to conventional silicon-based semiconductor devices. For example, InGaAs/InAlAs materials may preferred in ULSI applications due to their large conduction-band offsets and high carrier mobility. Schottky-gated InGaAs high electron mobility transistors (III-V HEMTs) grown on InP substrates have produced maximum transconductance (gm) values and have been shown to compare favorably in terms of a power-delay product.